Lubricant



- Patented Got. 320, 1945 zest,

LUBRICANT Q Robert D. Herlocker, Hammond, and Milton Paul Kleinholz,East Watkins, Chicago, Ill., assignors to Sinclair Refining Company, NewYork, N. Y., a corporation of Maine Chicago, 1116., and Franklin M.

No Drawing. Application April 24, 1943-.

Serial No. 484,471

Claims. (Cl. 252-50) This invention relates to an improved turbine oil.It relates more particularly to a lubricating oil composition consistingprincipally of apetroleum lubricating oil, the characteristics of theoil being modified by the addition thereto of a relatively smallproportion of a, diaminomethane derivative of the class represented bythe structural formula:

where R1N is a piperidino radical; R2 is either 7 hydrogen or an alkylor an aryl radical, R3 and R4 are alkyl or aryl radicals or else NRIiRAis a second nitrogen-containing heterocyclic radical, for instancepiperidino. The piperidino radical may be represented by the structuralformula:

E2C\ CHz-CH: A lubricating oil composition to be used as a turbine oil,and especially in modern marine steam turbines, is subject to veryexacting reeuirements. Not only must it perform the ordinary function oflubricating the turbine over pro longed periods without interruption butusually it must serve as a coolant, to lubricate the gearing mechanism,to operate oil-actuated governors or control mechanisms having very nicetolerances and lubricate other auxiliary equipment.

Many lubricating oil compositions highly satisfactory for thelubrication of other mechanisms have been found wholly unsuitable foruse as a turbine oil. This is probably due primarily to the fact that innormal use turbine oils rapidly become contaminated with water. Whateverthe cause, it is generally recognized that the performance of a turbineoil is not predictable from conventional tests applicable to other oillubricants.

An essential characteristic of a satisfactory turbine oil is its abilityto avoid the rusting of the metal parts within the oil system of theturbine and auxiliary apparatus under operating conditions. 1

The use of many lubricating oil compositions, otherwise satisfactory asturbine oils, has re-' sulted in the rusting of metal parts within theoil system with consequent serious interference with the operation ofoil-actuatedgovernors and other parts depending upon close tolerances.The results of such rusting not only interfere with the operation of andtend to clog the deliportion of a diaminomethane derivative of the classpreviously identified herein. Compounds of this class found to beespecially eflective in inhibitin rusting under conditions usuallyencountered by turbine oils are those in which each nitrogen atom isincluded in a piperidino radical.

- Such compounds found to be especially eflective in the preparationof'our improved turbine oils of the present invention may he exemplifiedby the following:

Dipipeildino-methane, which we believe to be represented by thestructural formula:

Dipiperidino-ethane, which we believe to be represented by thestructural formula:

And phenyl dipipeiidino-methane, which we believe to be represented bythe structural formula:

' CHr-CHa CHr-CHQ mo N-on-N cm CHFCHQ 5 CHr-Ci where R2 is a phenylradical.

It will be understood that the foregoing specific compounds areillustrative of the class and that our invention is not limited to theuse of these particular compounds but contemplates the use of othermembers of the class in the compounding of our improved turbine oils.

Many of the compounds suitable for use in compounding our improvedturbine oils are known to the art and may be readily prepared by knownmethods. In general they can be'produced as condensation products ofamines and aldehydes.

For example, the dipiperidinomethane, referred to herein and in theappended claims, was prepared as follows: 91.5 grams of 93% piperidine(1 mole) was placed in a 250 c. c. Erlenmeyer flask. To this there wasadded portlonwise with In referring to dipiperidinomethane,dipipershaking over a period of minutes 44.1 grams idinoethane andphenyl dipiperidinomethane of 34% formalin (0.5 mole formaldehyde).Durherein and in the appended claims, we refer, reing this addition,considerable heat was evolved spectively, to the above-describedproducts, aland the temperatureof the mixture increased to A? though, ofcourse, we intend to refer by these about 1'10 F. Before the addition ofthe formalin terms to the same materials by whatever prowss solution wascompleted, two phases formed in the they maybe made. It isunderstoodthat ourflask, a lower aqueous phase and an upper orinvention is notpredicated uponthe identificaganic phase. The lower phase was separatedand tion of the addends as a matter of terminology. on salting out withpotassium carbonate yielded In our co-pending application" Serial No. 2c. 0.015 a red liquid. The upper'organic phase 484,470, filedconcurrently herewith, we have dewas distilled, four cuts being taken.The condiscribed and claimed improved turbine oils in tioris under whichthe cuts were taken. and the which the rusting characteristics of thelubricatamounts thereof wereas follows: ing oil constituent are modifiedby incorporating 15 therewith a small proportion of a diamlnomethanederivative of a class of chemical comherein. In said application we havedescribed and claimed speciflcallyturbine oils comprising compounds ofthe general class in which at least pholino radical. The presentinvention is directed to turbine oils in which the addend is The secondout was found by analysis, by the a specie of the general class in whichat least one one ofthe nitrogen atoms is included in a mor- DumasMethod, to contain 15% nitrogen as comof the nitrogen atoms, andadvantageously eac pared with the theoretical nitrogen content of isincluded in a piperidino radical. 1 15.38% for pure dipiperidinomethane.At 20 C. The turbine oils to which the present applicait had a specificgravity of 0.9269 and a refraction is specifically directed possesscertain adtive index of 1.4886. This second cutwals equivavantages 'overthose in which the morpholino lent to 81.6% of the theoretical yield.The avercompound is incorporated particularly with reuse molecularrefraction of several batches of the spect to prolonged effectiveness ofthe addend product thus prepared was found to be 56.57 as underconditions where considerable amounts of against a theoretical molecularrefraction of water become admixed with and areseparated 56-48 for puredipiperidinomethane. from the turbine on while in use. This advantageresidue. o 1. was a viscous, dark red 5 isparticularly apparent whererelatively smaller d. Y proportions of the addendare used.

Seven other preparations were made/following Though our presentinvention is independent the proceduresubstantlally as describedexceptof any theory as to the reasons for this beneficial ing a slightvariation in the purity of the result, it'appears-to be due, in partat-l'east, to

piperidine employed. The products were found 40 diflerences insolubility of the addends in water. to be substantially uniformlyeiiective in our im- For instance, dimorpholinomethane is, readilyproved turbine oil. soluble in water, even at room temperature, whileThe dipiperidinoethane referred to herein and the dipiperidinomethane issoluble in water. only .in the appended claims was prepared as follows:to the extent of about 0.45% to 0.50% at 140 1".

1'19 grams of 95% pure piperidine (z'moies) was The l bricating oilconstituent of our improved placed in a 3-neoked' flask, equipped withaturbine oil may consist of a petroleum lubricatstirrer, and there wasadded thereto 30 grams of ing fraction such as ordinary specified forturanhydrous potassium carbonate. To this mixbine oils. It may withadvantage'be a highly retime there was added 48.4 grams (1.1 moles) offined lubricating oil, for instance an acid-treated acetaldehyde over. aperiod of 2 hours, with petroleum lubricating oil fraction or one whichstirring, the mixture being kept at a temperahas been subjected tosolvent refining such as ature below F. during the addition, by cooling.phenol-treated fraction from East Texas crude. The reaction mixture wasallowed to stand-over- Solvent reiinedils have generally been ioundnight and the aqueous potassium carbonate layer more resistant toslut-18 1 8 n the m' removed. The organic layer was then filtered 55oils. For example. lubricating oils such as a and topped at atemperature of 155 R, and an 'phenol-treated-East Texas neutral (Sample1),

. grams of the product. t

absolute pressure of 4.5 millimeters of mercury and an 'acid treatedfraction from-a Mid-Conto remove any water and unreacted volatile tinentcrude, (Sample H), mm the'followind materials present. It was a darircolored liquid. characteristics have been used with advantage:

The phenyl dipip'eridinomethane referrcd'to Q herein and in the appendedclaims was prepared Bumble! o as follows: 184.2 grams or pure piperidine(1.5 moles), was placed in a 500 c. c. Erlenmeyer v an as: flask andthere was added thereto portlonwise, Fg i f; over a period of '10minutes withshaking. 19.!) I 2 grams (one mole) of benzaldehyde. Duringthis Wm" 22- addition the temperature of the mixturerose to Pour, 4.-. Iab u 1". The solution clouded butQbefore gmggggggg; 8. 31% permitting ittosolidify, 300 c. c. of hot ethyl 0mm residue oomlifib'iiii'rl na. MM35 alcohol was added. Upon cooling this mixture 70 M90 there wasobtained 159 grams of phenyl diii'ltt'tifm ifiasa" I plperidinomethaneas a white solid having a meltg flg ffgg 81%; 81 E, ing point ofit'd-178 F. From the mother liquor I rdN wigtic mihdh'j. II- 0. x 1: 0.13.115 and wash liquors there was obtained 15 additional 1 m Byincorporating a mind:- proportion of a compound of the nreviouslyidentified class in a. suitable lubricating oil constituent, rusting orthe For example, the incorporation of 0.05% of any one of the compoundsspecifically identified herein has been found to result in a theAmerican society of Testing Materials and designated, respectively, A.S. T. M. Specification D-655-42-T for Turbine Oils and Proposed forDetermining Oxidation Character- Turbine Oils, Section III, TechnicalCommittee C, A. S. T. M. Committee 13-2, July 2, Iss1,

der such conditions, they are compatible with known anthoxidants, forexample bis-(p-dimethyieminophenyi)masthene which may with advantage beused in conjunctiontherewith in our improved turbine oils in order tocombine high oxidation resistance with the anti-rusting characteristicsof our turbine oils.

In the compounding of our improved turbine oil, a small amount of anaddend of the aboveiurther to improve our turbine oil were used.

our present invention further to improve the properties thereof invarious respects. The previously noted bis-(p-dimethylaminophenyl)-methane has been used with special advantage .with respect to itsoxidation characteristics.

The following examples of turbine oils, and their characteristics withrespect to rusting, will Clean specimen, 1. e. no rust.

B++ Only trace of rust.

B+ Up to 5% of surface rusted.

.B 5% to 25% of surface rusted. c. C 25% to 50% of surface rusted. D 50%to-% of surface rusted. E 75% to of surface rusted.

The rusting characteristics of our improved turbine oils, having theindicated composition and in which the mineral oil constituent was thatpreviously identified as Sample I, were found to be cs follows: J AddendRusting Addend oonocntmcharactert n istio i i "'idfiTYfi "6135' 132+ pper ome one.

Do 0. 10 A Do 0. 20 A Do 0. 50 A Dipiperidinoethanm 0. 02 0 Do 0. 05 ADo L 0. 30 A Phenyl dipiperldinomethsnm 0. 02 B Do. 0. 05 A Do 0 20 A Asappears from the resultsoi these tests.

tection agninst rusting and, only a very small amount of where evensmeller proportions of the addend The oxidation induction period of theoil desigmeted flample I was hours. @270 of bis-(p-dime'thylmninophenyl)-methane in our improved turbine oil cont ng 0.1% and 0.3%,respectively, of dipiperidinomethcne has resulted in increasing theoxidation induction.

period of the turbine oil to as high as 825 hours and 850 hours. By thisinclusion, the rusting that, by the "use of relatively small proportionsof bis- (p-dimethylaminophenyl) -methane in conjunction with one of thediaminomethane derivatives previously identified,

The inclusion of test repeated until where smaller dino compounds uponconditions'oi use.

I about 0.01% portions even in excess of 1% may the rusting completeprotection portion of the same oil after oxidation hours did not givecom lete protection against rusting. Portions or the same Sample I,containing 0.2% dipiperidinomethane, were oxidized for '12. and 192hours, subjected respectively, and then to the a s. T. M. me test. Thesepre-oxidired against rusting. Another the test, they seemed to have orthe etching of the test specimen.

A further notable characteristic of our int-'- proved turbin oil is itsability to withstand cone tamination'bs water without materialseparation 01! the addend from the oil or substantial detenoration o!the addend itself.

As previously noted herein, our improved turbine oil oi! our presentinvention has been found to be'especially resistant to extraction or theaddend from the oil by water. This is illustrated by results ofThereafter, the water is again removed and the rusting of in this mannerour turbine oil comprising 0.1% or dipiperldinomethane,-rusting wasrepeated seven times while, or dimorpholinomethane, peared on the thirdbest. Using 0.2% of either or these addends, the rusting inhibition wasmaintained throughout eight successive tests but,

proportions oi the respective adused, the characteristic of the piperiatrace of dends. were traction by water tage.

As we have previously stated herein,

is frequently a. distinct advandependin the addend may with ad- "be usedin proportions ranging from to 1% by weight or the oil. Provantage suchlarger-proportions round necessary. Though proportions less than 0.01%maybe used, such smaller proportions are usually not suiilcientlyeilective. Accordin8- tests in which the prescribed rusting- 9 mm theclass the test specimen I rusting apof increased resistance to exbut 1y,proportions ranei s from about 0.01% to ab ut 1% are generallyrecommended;

We claim:

1. An improved turbine oil petroleum lubricating tion,'enective toretard rusting, or a diaminO methane derivative of the class representedby the structural formula which comprises a /R hat-ca! 1 l R: where BINis a piperidino radical, Re is selected from the class consisting ofhydrogen, alkyl and aryl radicalsand NRaRs is a radical selected fromthe class consisting of nitrogen-containinll heterocyclic radicals andnitrogen-contain! radicals wherein R3 and R4 are either alkyl or a ry r2. Animproved turbine oil which comprises a petroleum lubricating oilcontaining from about 0.01% to about 1% of a diaminomethane derivativeof the class represented by the structural formula V mN-cn-u 1!: Bl

where RiN is a piperidino radical, R2 is selected 0.05% to about 1%methane. v

ROBERT .no 211;! MILTON PA mom. WATER oil containing a propor-

